Spiral conveyer flight and method of making the same



Feb. 25, 1930.

J. D. CHRISTIAN 1,748,206 SPIRAL CONVEYER FLIGHT AND METHOD OF MAKING THE SAME Pi1ed.July 15, 1926 2' Sheets-Sheet 1 INVENTOE I J05 1.30/1 0. C fir/1sf/on Br A? 4 T'TOENEYS Feb. 25, 1930. J. D. CHRISTIAN 1,748,206

SPIRAL GQN VEYER FLIGHT AND METHOD OF MAKING THE SAME Filed July 15 1926 2 Sheets-Sheet 2 //v VEN 7012 Joseph 0. C/M/sf/an I av x v Patented Feb. 25, 1930 UNITED STATES PATENT OFFICE- J'OSEPH D. CHRISTIAN, OF SAN FRANCISCO, CALIFORNIA SPIRAL CONVEYEE FLIGHT AND METHOD OF MAKING THE SAME Application filed July 15, 1926. Serial No. 122,549.

The, invention relates to a spiral or helicoidal conveyer flight for a screw conveyor or spiral conveyor and particularly to a method of and an apparatus for making such conveyer flights. Conveyor flights of the type The invention possesses other advantageous features, some of which with the foregoing, will be set forth at length in the following description, where I shall outline in full that form of my invention which I have selected for illustration in the drawings accompanying and forming part of the present specification. In said draWings'I have shownone form of apparatus embodying my invention but it is to be understood that I do not limit myself to such form, since the invention, as set forth in the claims, may be embodied in a plurality of forms.

Referring to said drawings:

Fig. 1 is a side elevation of a machine embodymg my invention and adapted to be used for squeezing split annular discs into helicoidal form.

Fig. 2' is a perspective view of the top or movable swage or die which is cinployed in squeezing the flat annular disc to helicoidal form.

Fig: '3 is a perspective view-of the stationary lower swage or die with which the upper swage cooperates.

Fig. 4 is a perspective view of a split annular disc being formed into a helicoidal flight.

Fig. 5 is aperspective view of a split aunular disc before it is operated upon by the swages.

Fig. 6 is a .form of disc.

In accordance with my invention, I have perspective view of a modified provided a method whereby the helicoidal flight of a conveyer may be made of man- .ganese steel, an accomplishment which heretofore has not been attained. In practicing my method, I cast a split annular disc of manganese steel, as set forth in my co-pending application above identified, and squeeze or press the split annular disc into helicoidal form, to produce helicoidal conveyer flights.

The annulardisc is preferably permitted to cool after being cast, and is squeezed or pressed into helicoidal form in cold condition. The forming is accomplished by placing successive segmental portions of the disc between swages or dies having segmental helicoidal faces and moving the dies together to press the segmental disc portions into helicoidal form. The disc is gradually rotated about its axis while it is interposed between the dies, so that successive segments of the disc are successively brought under the action of the die. In converting the flat disc into a helicoidal flight, the inner and outer edges of the annular disc are stretched. Due to the smaller diameter of the inner edge, such edge is stretched to a greater degree than the outer edge since in a helicoidal flight the innc r edge extends longitudinally for the same distance as the outer edge. After the forming or squeezing operation, the end edges of the flight are radially disposed with relation to the axis of the helicoid so that successive flights which are combined to form a conveyer register accurately at their edges. The flights may then be readily joined in any suitable manner, as set forth in my aforesaid application.

In the practice of my invention, the split annular-steel disc 2 is 'squeezed or pressed between upper and lower swages 3 and 4.

The lower swage is preferably held stationary and the upper swage is reciprocated with respect to the lower swage to press or squeeze an'interposed disc. The lower swage 4 is provided with a segmental helicoidal surface i 5. At its outer edge, the swage 5 is provided with a shoulder 6 which forms a guide a ainst which the outer edge of the disc is p aced. 'lhe shoulder 6 is formed substantially on the arc of a circle corr sponding to the diameter of the disc, from which the flight is formed. In order to form the flight into a helicoid, the angle of inclination of the inner edge 7 of the swage 4 is made greater than the angle of inclination of the outer edge 8, so that the inner edge of the disc is bent or squeezed to a much steeper angle than the,

outer edge. The inclination of both the inner and outer edges 7 and 8 is greater than the desired inclination of the helicoidal flight. The resiliency of the manganese steel is such as to cause the flight to spring bacltward after it has been squeezed between the swages and by increasing the angle of inclination to a degree which is greater than the desired degree, the springing back of the metal brings the resulting angle of inclination of the edges of the helicoid to the desired value. The upper swage 3 is provided with a helicoidal face 12 which is complementary to the helicoidal face 5 and the inner and outer edges 13 and 14 of the upper swage are complementary to edges 7 and 8 of the lower swage. The lower swage is preferably provided adjacent its rear edge with a plurality of upstanding pins or studs 15 which assist in positioning the flight between the swages.

The pitch of the cooperating helicoidal surfaces 5 and 12 increases from their outer edges toward their inner edges and means are provided for taking advantage of this condition so that different flights can be squeezed to different pitches or the same flight may be squeezed to a varying pitch.

The lower swage 4 is provided with one or more arcuate grooves 16 and 17, opening onto the helicoidal surface 5, and the edges of these grooves are preferably concentric With each other and with the shoulder 6. When 1t is desired to increase. the pitch of the flight being squeezed, the outer edge of the flight is positioned against one of the rear edges 16 or 17 of the grooves 16 and 17. With the flight in such position, the application of pressure will squeeze the flight to a greater pitch than would be obtained if the outer edge of the flight were in engagement with the shoulder 6. The grooves 16 and 17 also serve to receive bosses or abutments 2O on the surface of the disc, as the disc is being sent thru between the dies, so that the presence of these bosses or ahulments will not interfere with the formation of the flight. The lower swage 4 is provided also with a radial groove 18 to receive bosses on the disc when such bosses are in such position or of such size that they will not enter either of the grooves 16 or 17. As shown in Figs. 5 and 6. the discs may be provided on their ends with radial flanges 20 or ears 21 which serve as means for securing successive flights together to form a conveyer. These radial flanges or cars may also be received by the groove 18 while the disc is being squeezed.

The upper swage 3 is preferably mounted on a bracket 22 which is secured to the reciprocating head 23 of a suitable press 24. The press operates to reciprocate the upper swage 3 vertically with respect to the lower swage, to squeeze an interposed disc or flight.

The control of the operation of the press may be accomplished by a foot lever (not shown) suitably connected by a rod 25 to a clutch 26 in the press. The upper and lower swages 3 and i are preferably arranged on overhanging brackets so that clearance is provided above and below the swages for the flight as it being formed. This clearance is particularly desirable above the upper swagc, since the flight as it isbeing formed curves upward. In order to provide sufficient clearance for the movement of the upper swage, the two swages are preferably positioned so that the axes of the helicoidal surfaces of the swages are inclined to the line of motion of the upper swage, and the axis of the formed helicoid is then also inclined to the axis of movement. This causes the upper end of the helicoid to be raised and pass over'the upper die as the helicoid is being formed. The reciprocation of the upper die is restricted to a small distance to provide suflicient clearance above the die for the formed helicoid. When the apparatus is used to form flights from split annular discs of manganese steel, that portion of the disc which lies diametrically opposite the split is preferably first intro-.

duced between the swages so that the two ends of the disc lying next to the split become separated and the disc may then be easily passed thru the swages. It is understood that the disc is gradually rotated about its axis as the die is reciprocated and that successive segments of the disc are successively squeezed to helicoidal form. It may bcnecessary to give each segment of the disc a plurality of squeezes to bring it to the desired form, or the metal of the disc maybe of such' thinness that one squeeze on each segment is sufficient. The disc is gradually and slowly advanced between the dies as the upper die reciproeates so that a smooth, clean helicoidal flight is formed.

' I claim:

l. The process of making a screw conveyor flight which comprises casting a split annular metallic disc and'warping successive segments of the disc to helicoidal form.

2. The process of making a screw conveyor flight which comprises casting a split metallic disc and warping successive. segments of the disc to a helicoidal pitch whichis greater than the desired pitch, so that the spring in the metal returns the flight -to the desired helicoidal pitch. I

The process of making a screw conveyor flight which comprises casting a split annular metallic'disc and successively subjecting successive. segments of the disc to pressure applied substantially in-the direction of the limit to give it a and squeezing the disc while cold to helicoidal form.

6. The process of maklng a manganese steel screw conveyer flight which comprises casting a split annular disc of manganese steel, permitting the cast disc to cool and squeezing successive segments of the cold disc by pressure applied substantially in the-direction of the axis of the disc. to a helicoidal form of greater pitch than the desired helicoidal pitch, so that the spring in the steel returns the segments to the desired helicoidal itch.

p 7. An article of manufacture adapted to be formed into a screw conveyer flight comprising a .splitannular cast disc of manganese steel.

,8. The process of making a manganese steel screw conveyer flight which comprises casting a split annular disc of manganese steel, and stressing the disc beyond its elastic permanent set in the shape of a helicoid.

.9. The process of making a manganese steel screw conveyer flight which comprises casting a split annular disc of manganese steel, permitting/said cast disc to cool, and

stressing the cold disc to give it a permanent set in .the spape of a helicoid.

10. The rocess of treating manganese steel which comprises casting a blank of manganese steel,\and deforming said blank to The process of obtain a permanent set in a substantially different shape.

11. Theprocess of producing a manganese steel article of selected shape which comprises casting a manganese steel blank of a different shape, and treating said blank to give it a permanent set in said selected shape.

12. The process of producing an article of selected shape which comprises casting a manganese steel blank of a different shape,

permitting said blank to cool, and deforming said cold blank to said selected shape.

13. The process of treating manganese steel which comprises casting a manganese steel blank, and successively warping suc cessive portions of said blank to substantially different shapes.

14. The process of producing a manganese steel article of selected shape which comprises casting a split manganese steel blank of a different shape, and deforming successive portions of said blank to'said selected shape.

producing a manganese steel article of selected shape which comprises casting a manganese steel blank of a different shape, permitting said blank to cool, and successively deforming portions of said cold blank into said selected shape.

16. The method of making manganese steel conveyer flights which comprises casting an annular manganese disk, shaping the disk into a permanent helicoidal form by warping the disk to a pitch greater than that of the permanent form by subjecting the disk while cold to successive pressures between complementary members.

17. The process of making a manganese steel conveyer flight of selected shape, which comprises casting a split annular blank of manganese steel of different shape and warping successive portions of the blank to obtain a permanent set in the selected shape of the conveyer flight.

In testimony whereof, I have hereunto set 

